green_antarctica_the_last_continentfandomcom-20200215-history
About climate and geography
I'd expect that the extreme highlands would be glaciated. So a stretch of coastal area, a blob in the center, and the long island chain. Two of the principal glaciation areas There are four major lowland areas, one relatively hilly, which would make potentially fertile regions, with some geographical barriers encouraging speciation. The moderate highlands would be roughly equivalent to taiga or tundra. Also, lots of islands, probably wet and uncomfortable. Might be useful to set about naming the features. ------ In terms of interesting geography, there's a channel between the main continent and the long island chains that runs through the geographical center of Earth's axis. Wicked cool. I be there are some crazy scary currents. On the map you linked it looks like that channel doesn't quite cut all the way through and is fairly narrow elsewhere so even if it did there probably won't be any currents flowing directly over the south pole. Don't forget that with fewer glaciers the continental shelf will have a large amount of rebound. Most of those channels will be dry land. Well, okay it's not rebound. It just never gets depressed in the first place. -- Well, I dunno, it's always seemed like perfectly happy bedrock to me. I would anticipate some degree of rebound or non-depression. But as I understand it, this wouldn't dramatically affect the topography of the bedrock. I believe that it would simply make the local coastlines more difficult to predict within a few hundred meters, and to varying elevations. I assume, somewhat arbitrarily, that non-depression would be most modest around the edges of the system. So you'd get a channel, or at least two immense funnel shaped shallow bays bisecting one side of Antarctica from another. I dunno, you guys may be right, and in terms of distribution and dispersal of flora and fauna, it makes it a lot easier to have the two land masses actually connected. But I am powerfully attracted to the notion of a strange and forbidding channel through the center of the world, mighty cataracts and a towering mist, and birds shrieking "Tekeli-Li Tekeli-Li" I'd be happy to concede the channel as a relatively recent geological development, perhaps over the last five or fifteen million years, which would allow for a pretty good penetration of South American forms through the whole continent. -- Here's a more detailed map of the area showing the same thing: ------ Well, for two reasons, I'm going to argue that it does. First: there are some interesting things going on here. The area is probably not subject to tides in the same way that other areas are, but there will be seasonal tidal effects which are likely to be significant. Potentially more significant is that this waterway literally sits on the axis of the South Pole itself. That means that the entire world is spinning around this channel, or these two funnel bays, if you will. For the south pole, this leads to coriolis or circular winds, and perhaps partially to coriolis currents, the antarctic circumpolar current. I'm not a physicist, but I'd argue that the coriolis forces of Earth's spin would be a unique engine driving water currents in. I'd also argue that regardless, the circumpolar current would probably force water up one or the other, or both bays. Note the shape, both bays are essentially large funnels. That means that as water moves in, there's less and less space, so it tends to pile up. Water does pile up. In my old homeland, there's a place called the Bay of Fundy, essentially a funnel shaped bay at the juncture of Nova Scotia and New Brunswick. Tidal water entering the bay is forced up. Fundy has tides ranging from 50 to 70 feet at its end, which enter as a single wave. Used to be very impressive. Bay of Fundy Another interesting place where water behaves is Lake Winnipeg, a loosely hourglass shaped lake roughly the surface area of one of the great lakes, in the Canadian province of Manitoba. An Engineer who works with the lake once told me that wind from north to south would pile up water so that lake levels were as much as nine feet higher in the south basin than the north basin. WINNIPEG AND THE EFFECTS OF HECLA ISLAND Now, comparatively, Bay of Fundy and Lake Winnipeg are comparatively small water funnels compared to what we're looking at in Antarctica. So, I'd argue that combinations of currents, tides, winds and coriolis forces could easily pile up waters to the point where they'd overtop low bedrock barriers, resulting in local flooding and eventual drainage through. Even if it didn't overtop, you'd have a hell of an erosional mechanism, and on top of that, you'd have the erosional effects of freeze and thaw, which are pretty brutal all by themselves. So I'd argue that the cumulative effect of currents and erosional processes would cut the channel straight through. I'd suggest that everything considered, the 'cut through' points would amount to pretty nasty and ferocious rapids, possibly technically above sea level, and would make for a crazy, weird, scary sea voyage.... much as described in the Narrative of Arthur Gordon Pym. Second: I invoke the 'rule of cool', which as we know, trumps physics and logic. I'm typing with my shades, daddy-oh, can you dig it? ------------ I don't like doing this to a good map, but I think you and DValdron may have overlooked something here.... Correct me if I'm wrong, but what I have been aware of all this time is that massive glaciation of a land will push the land down. Without ice burden pressing the continent down for more than 20 million years, the general elevation of the continent should be higher, and thus the ATL continent should have more land above sea level. This world's Antarctica have more land compared to Antarctica in the map, in a world with global sea level 100 meters higher than ours.... - The map's based on this map (see above) of the Antarctic bedrock, which as you rightly say has been depressed by the weight of this ice. However without all that water locked up in the ice, the sea level will be higher. I think for convience DV just assumed that the two effects - isostatic rebound and higher sea levels cancel each other out. I think he just handwaved the effects of sea level on the rest of the world so he can have characters such as Cook turn up. Obviously this is only my interpretation of DV's thinking on the issue. 1) Thing is, would Antarctica alone be enough to strain the sea level ? DValdron's idea of putting the waters as additional ices in the Arctics and maybe other icy areas sounds as a more subtle way to do that.... That Antarctica you linked to doesn't actually look much different to Green Antarctica - the only real difference I can see is the lack of the Sea of Tranquility (Paant'n Lul). 2) Most visible difference, yes. But there is also the big island between Tsaotuhgua Lui and Khihrui(?) Lui that in that other Antarctica being a Peninsula. And generally a bit chubbier continent and more islets surrounding. Also do you think the map's too dark? 3) Yes, it is. ---- The problem with Isostatic depression rebound is that it's effectively impossible to seriously model the effects. Assume that most of the Antarctic continent is under 2000 meters of ice. What does that mean for rebound? I don't think it means that the entire continent uniformly lifts hundreds of meters everywhere. What it seems to mean is more pronounced elevation towards the center of the land mass, and some unpredictable but minimal elevation around some, but not necessarily all shorelines. How much? One meter? Ten? A hundred? hard to say. It's complicated further in this case, because we have an Antarctica which, except for three principle glacier areas, does not suffer isostatic depression at all. The place, in this timeline, was never under 2000 meters of ice. So little in the way of depression, no rebound issues, its always been stable. Ergo, for our purposes, I regard the significant effects as minimal and essentially unquantifiable. Some of the highlands might be higher. Some hilly areas may be more pronounced. Some shorelines might extend further, some Islands may be part of shore, some reefs may now be islands. Can we define which and where? Not a chance. Take another look at the map. It's basically defining colour increments as fluctuations of 2500 feet. Thus, light blue represents a depth of 0 to 2500 feet. Medium blue represents a depth of 2500 to 5000 feet. In the other direction, dark green represents a depth of 0 to 2500 feet, light green, 2500 to 5000 feet. Within that range, we can't automatically assume the depth or rebound characteristics of any particular area. Conceivably, for instance, you could elevate all Antarctica by a full thousand feet, which I'd dismiss as ridiculous, and not change a single feature of the map. You''d just make seas shallower, and lands higher.'' Of course, its not realistic to uniformly elevate by a thousand feet, just as its not realistic to assume that the light blue area is uniformly 2500 feet or 1500 feet. Within the green, there will be shorelines very close to sea level, and significant elevations beyond that. Within the light blue there will be shorelines close to sea level, but depths which reach hundreds of meters in short time. But where and which and how high or low are impossible. Essentially, with the information we have available to us, there is no real way to gage, in detail, the effects of Isostatic depression on the different regions of Antarctica, particularly hypothetical shorelines. Even if we could, that would not necessarily predict isostatic rebound. And depression and rebound would not allow us to predict the steady state of a continent never glaciated. It is entirely possible that Antarctica's natural shorelines look very different, that there is more land, smaller seas and that the large islands are all connected. But it is also entirely possible and highly likely, that Antarctica's shorelines would look pretty much like they do now, with seas, islands, coasts basically where they are. Indeed, within the context of the map, the latter is more likely, given the extremely wide ranges of depth. As I've said, elevate everything 1000 feet, and its possible nothing much changes. Local shoreline elevations of 100 feet or more may not significantly change anything on the scale of map that we have, which literally reduces a four million square mile continent to a four inch blot. Of course, local coastline features, the sort of thing beyond the resolution of the map we've got could vary dramatically and are likely entirely unpredictable and therefore somewhat arbitrary. But as noted, this goes beyond the scale of the map, and are therefore subject to authorial fiat. Basically, I take the view that the map features we have are both sufficient and adequate. There's no real benefit into trying to estimate or guesstimate alternatives, and there's no basis to assume or predict validity of alternatives. As for the guy you linked too. He does interesting things, I like a lot of his worlds. I'm not so thrilled with his habit of peopling them with a variety of crudely drawn, big eyed, smiling, friendly sapient critters, but that's his lookout. And while I like a lot of his stuff and find much of it well reasoned, I don't necessarily agree with everything. Anyway, I hope that you take these comments in a decidedly non-Tsalal fashion of good spirits and amicability. -- I see. Besides I can see a little bit of geographical changes will negate Yag culture and can possibly disrupt many other of your plans and seemingly-plans here... :) Possibly, or possibly not. At the level of detail that's available to us, changes are as arbitrary as no changes. If all possibilities are equal, I have as much basis to not change the map as to change it. Looking at Ornithia, on Seapole, in WorldDreamBank, he's got some problems. He's postulating a large internal desert close to the sea with a major ocean inlet and a multitude of glacial rivers draining into it. Yikes, no way that's viable. I notice his 'sea access' to the desert is actually across high bedrock rather than lowlands or actual sea access. Same problem on the other side, he puts a large gulf or bay where one doesn't exist. Is any of this bad? No, its a creative reinterpretation. From the looks of it, its hand painted, and its a depiction of a future, so that allows for certain liberties. But it doesn't match closely with the published antarctic geology that we're using. Actually, for the most part, the major features - The three glacial highland/mountain ranges. The lands of Tsalmothua, Yag, Azul, Ptarh and Wang-Gash would probably continue to exist in some form or other sufficient to support my narrative. In relation to Yag, like it or not, a glacial mountain range is going to calve icebergs into the sea on one side and drain into the lowlands on the other. Which then translates into water fed, seasonally flooding lowlands. Which then gets us Yag. About the only thing that's really at risk is the cross polar channel, and that you'll have to take up with Poe. I invoke the rule of cool. In any event, I'm not concerned. Any alternate history involves certain implausible (ie, non 0TL) events. I've made arbitrary decisions along the way. So be it. --- By the way, nice to see a lighter episode to give us some break here.... ;) I should mention that when Captain Cook comes to Antarctica, he falls into the hands of the Yag. I'm champing at the bit to get there. :D --- I just don't like seeing this thread drowned from the first page. Bump !! :D:D This is an amazing and horrifying work of art you have created here. Before reading this, I don't believe I had ever entertained thoughts of purging Antarctica with nuclear fire...